Trans-cinnamyl Alcohol Research Articles

Enantio-and stereo-selective route to the taxol side chain via asymmetric epoxidation of trans-cinnamyl alcohol and subsequent expoxide ring opening

The first route to the side chain of Taxol and Taxotere, employing asymmetric epoxidation (AE) of trans-cinnamyl alochol and a new highly regio- and stereo-selective opening to the epoxide ring with MgBr2, is described.

Substrate specificity, regiospecificity and stereospecificity of halogenation reactions catalyzed by non‐heme‐type bromoperoxidase of Corallina pilulifera

Many organic compounds were found to be substrates for halogenation reactions catalyzed by the non-heme-type bromoperoxidase found in the red alga Corallina pilulifera. Anisole, 1-methoxynaphthalene and thiophene were converted to o and p-bromoanisoles, 1-methoxy-4-bromonaphthalene and 2-bromothiophene respectively. Regiospecificity of the enzymatic bromination of anisole was tested and found to be the same as in the chemical reaction with NaOBr. The enzyme also acted on substituted alkenes such as styrene, cyclohexene, trans-cinnamic acid, trans-cinnamyl alcohol and cis-propenylphosphonic acid, to give the respective bromohydrin compounds or decarboxylated bromo compound. These bromohydrin compounds were always mixtures of stereoisomers. In the light of the above findings together with the previous studies concerning the halogenation mechanism, the bromoperoxidase of C. pilulifera was considered to have no specific restriction site for these substrates.

Geometric specificity of alcohol dehydrogenases and its potential for separation of trans and cis isomers of unsaturated aldehydes.

The geometric specificity of three different alcohol dehydrogenases (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) (from yeast, from horse liver, and from Leuconostoc mesenteroides) in the reduction of trans- and cis-cinnamaldehydes has been investigated. All three enzymes display a remarkable trans specificity: they react with the trans isomer 7 to 647 times faster than with its cis counterpart. Experiments with the enzymatic reduction of 3-phenylpropionaldehyde, a saturated analog of cinnamaldehyde, have revealed that whereas trans-cinnamaldehyde possesses the "right" configuration for the active centers of the alcohol dehydrogenases, the cis isomer apparently does not fit the active centers well. All three alcohol dehydrogenases studied also exhibit a marked trans specificity in the reaction with alpha-methylcinnamaldehyde. The geometric specificity of alcohol dehydrogenases can be used for the production of otherwise hard to synthesize cis isomers of unsaturated aldehydes from their readily available trans counterparts: trans-cinnamaldehyde was irradiated with ultraviolet light (which converted it to a mixture of trans and cis isomers) then treated with NADH and yeast alcohol dehydrogenase (which selectively reduces only trans aldehyde into the alcohol), and finally the mixture of cis-cinnamaldehyde and trans-cinnamyl alcohol was separated easily by preparative column chromatography.

The aroma of cranberries

Volatile components of European and American cranberries were studied by combined gas chromatography-mass spectrometry. A total of 70 components were identified, corresponding to about 16.1 ppm and 3.7 ppm of the total volatile oil, in European and American cranberries, respectively. The aroma of cranberries is characterised by the presence of several aromatic compounds together withα-terpineol. More than 35 compounds not reported previously as cranberry volatiles were identified. These included terpinolene, p-mentha-1,8-diene, thujene, p-mentha-1,8-diol, carvenone, 1-phenylethanol, 3-phenylpropan-1-ol,trans-cinnamyl alcohol, 2-(4-hydroxyphenyl)-ethanol, 2-(4-methoxyphenyl) ethanol, salicylaldehyde, 4-methoxybenzaldehyde, 3-phenylpropanal,trans-cinnamaldehyde, vanillin, 4-hydroxyacetophenone, 4-methoxyacetophenone, 4-(4-hydroxphenyl)butan-2-one, 4-(4-hydroxy-3-methoxyphenyl)butan-2-one, methyl cinnamate, 2-phenylethyl formate, and someγ-andα-lactones. p-Methan-1,8-diol (terpin hydrate) has not been identified in any berries or fruits. In general, the concentrations of the individual components in European cranberries were 4–5 times higher than in American berries.

Stereochemistry in oxidation of allylic alcohols by cell-free system of callus induced from Cannabis sativa L.

In the cell-free system of callus induced from Cannabis sativa L. (Moraceae), the pro-R hydrogen from C-1 methylene of primary allylic alcohols such as trans-cinnamyl alcohol and geraniol was abstracted. In an example of secondary allylic alcohols biotransformations, S-(-)-isophorol of the racemate was biotransformed to isophorone, and (+)-trans-verbenol of four isomers, such as (+)-and (-)-trans-verbenol, and (+)-and (-)-cis-verbenol, was preferentially biotransformed to (+)-verbenone. We reported previously that the enzyme which catalyzed the oxidation of these allylic alcohols in the cell-free system of Cannabis callus was an alcohol oxidase.

Stereochemistry in oxidation of primary allylic alcohols by cell-free system of callus induced from Cannabis saliva L.

The pro-R hydrogen from C-1 methylene of primary allylic alcohols as geraniol and trans-cinnamyl alcohol was abstracted in cell-free system of callus induced from Cannabis sativa L.

The Preparation of Specifically Deuterated trans- Cinnamyl Alcohol and trans- Cinnamic Acid

The reduction of ethyl phenylpropiolate by lithium aluminum hydride results in partial reduction of the triple bond to give trans-cinnamyl alcohol. If ethyl phenylpropiolate is reduced by LiAlD4 followed by work-up with acetone and H2O the product is the specifically labeled compound, trans-3-phenyl-2-propen-1-ol-1,1,2-d3. If the ester is reduced with LiAlH4 followed by work-up with acetone-d6 and D2O the product is trans-3-phenyl-2-propen-1-ol-O,3-d2. Oxidation of these two products by sodium ruthenate leads to formation of trans-cinnamic acid-α-d and trans-cinnamic acid-β-d, respectively.

Oxidation of Organic Compounds with Xenon Trioxide I: Stoichiometric and Kinetic Studies Involving Cinnamyl Alcohol, Cinnamaldehyde, and Cinnamic Acid

The stoichiometry involved in the xenon trioxide oxidation of cis- and trans-cinnamyl alcohol, trans-cinnamaldehyde, and trans-cinnamic acid to carbon dioxide and water was determined using an excess of xenon trioxide. The rate of oxidation of trans-cinnamaldehyde with xenon trioxide within the concentration range studied, was found to be first order with respect to xenon trioxide and zero order with respect to trans-cinnamaldehyde. The reaction rate is pH-dependent and inversely related to the ionic strength of phosphate buffer.

Oxidation of Alcohols with t-Butyl Chromate. II. The Oxidation of Primary Aromatic Alcohols

Abstract The oxidation with t-butyl chromate has been carried out with benzyl alcohol, its p-substituted derivatives and trans-cinnamyl alcohol, and also with β-phenylethyl alcohol. In the former alcohols, the corresponding aldehyde was obtained as the main product, but the corresponding ester was not formed. On the other hand, the latter alcohol, containing a methylene group adjacent to the hydroxymethyl group, produced the corresponding ester, aldehyde and acid, as in the case of a saturated primary aliphatic alcohol.